From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 221BDC433EF for ; Wed, 1 Dec 2021 16:19:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349550AbhLAQWw (ORCPT ); Wed, 1 Dec 2021 11:22:52 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43146 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232207AbhLAQWt (ORCPT ); Wed, 1 Dec 2021 11:22:49 -0500 Received: from sin.source.kernel.org (sin.source.kernel.org [IPv6:2604:1380:40e1:4800::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2B8ABC061574 for ; Wed, 1 Dec 2021 08:19:28 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id 44894CE1FB5 for ; Wed, 1 Dec 2021 16:19:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BB4F2C53FCC; Wed, 1 Dec 2021 16:19:23 +0000 (UTC) Date: Wed, 1 Dec 2021 11:19:22 -0500 From: Steven Rostedt To: Masami Hiramatsu Cc: LKML , zhangyue , naveen.n.rao@linux.ibm.com, anil.s.keshavamurthy@intel.com, davem@davemloft.net Subject: Re: [PATCH] kprobes: Limit max data_size of the kretprobe instances Message-ID: <20211201111922.2c52047d@gandalf.local.home> In-Reply-To: <163836995040.432120.10322772773821182925.stgit@devnote2> References: <163836995040.432120.10322772773821182925.stgit@devnote2> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 1 Dec 2021 23:45:50 +0900 Masami Hiramatsu wrote: > The kretprobe::data_size is unsigned (size_t) but it is > used as 'data_size + sizeof(struct kretprobe_instance)'. > Thus, it can be smaller than sizeof(struct kretprobe_instance) > while allocating memory for the kretprobe_instance. The above doesn't make sense. data_size is unsigned but it is used as 'data_size + sizeof(struct kretprobe_instance)'. What does that mean? What can be smaller than sizeof(struct kretprobe_instance) and why does it matter? -- Steve > > To avoid this issue, introduce a max limitation of the > kretprobe::data_size. 4KB per instance should be OK. >